/*
 * Copyright 2014 Actelion Pharmaceuticals Ltd., Gewerbestrasse 16, CH-4123 Allschwil, Switzerland
 *
 * This file is part of DataWarrior.
 * 
 * DataWarrior is free software: you can redistribute it and/or modify it under the terms of the
 * GNU General Public License as published by the Free Software Foundation, either version 3 of
 * the License, or (at your option) any later version.
 * 
 * DataWarrior is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License along with DataWarrior.
 * If not, see http://www.gnu.org/licenses/.
 *
 * @author Thomas Sander
 */

package com.actelion.research.gui;

import java.awt.*;
import java.util.ArrayList;
import javax.swing.JPanel;
import java.awt.event.*;

/**
 * Lightweight Slider for maintaining two values within given limits
 */

public class JPruningBar extends JPanel implements MouseListener, MouseMotionListener {
	static final long serialVersionUID = 0x20070307;

	private static final Color cShadowColor		 = new Color(153, 153, 153);
	private static final Color cDarkShadowColor	 = new Color(102, 102, 102);
	private static final Color cThumbColor		  = new Color(153, 153, 204);
	private static final Color cThumbShadowColor	= new Color(102, 102, 153);
	private static final Color cThumbHighlightColor = new Color(204, 204, 255);
	private static final Color[] cWaterBlueColor = {
							new Color(188, 216, 248), new Color(184, 215, 247),
							new Color(170, 205, 245), new Color(150, 194, 242),
							new Color(116, 172, 235), new Color(138, 190, 243),
							new Color(146, 196, 247), new Color(155, 203, 252),
							new Color(164, 208, 255), new Color(170, 215, 255),
							new Color(177, 223, 255), new Color(193, 235, 255),
							new Color(207, 245, 255), new Color(207, 255, 255) };
	private static final Color[] cWaterRedColor = {
							new Color(255, 189, 219), new Color(247, 189, 215),
							new Color(247, 173, 207), new Color(247, 148, 195),
							new Color(239, 115, 174), new Color(247, 140, 190),
							new Color(247, 148, 199), new Color(255, 156, 203),
							new Color(255, 165, 211), new Color(255, 173, 215),
							new Color(255, 181, 223), new Color(255, 198, 235),
							new Color(255, 206, 247), new Color(255, 206, 255) };
	private static final int cOverallWidth = 16;
	private static final int cThumbHeight = 14;
	private static final int cBorder = 2;

	private float	mLowValue,mMinValue,mHighValue,mMaxValue,mSegmentSize;
	private boolean	mIsHorizontal,mUpdateNeeded,mUseRedColor;
	private int		mID,mMousePosition,mClickedArea,mPosition1,mPosition2;
	private ArrayList<PruningBarListener> mListener;

	public JPruningBar() {
		init();
		mHighValue = 100;
		mMaxValue = 100;
		}

	public JPruningBar(boolean isHorizontal) {
		init();
		mHighValue = 100;
		mMaxValue = 100;
		mIsHorizontal = isHorizontal;
		}

	public JPruningBar(boolean isHorizontal, int id) {
		init();
		mHighValue = 100;
		mMaxValue = 100;
		mIsHorizontal = isHorizontal;
		mID = id;
		}

	public JPruningBar(float min, float max, boolean isHorizontal, int id) {
		init();
		mMinValue = min;
		mLowValue = min;
		mHighValue = max;
		mMaxValue = max;
		mIsHorizontal = isHorizontal;
		mID = id;
		}

	public void paintComponent(Graphics g) {
		super.paintComponent(g);

		Dimension theSize = getSize();

		if (mUpdateNeeded) {
			int x1,y1,x2,y2;
			if (mIsHorizontal) {
				x1 = cBorder;
				x2 = theSize.width - cBorder - 1;
				y1 = (theSize.height - cOverallWidth) / 2;
				y2 = y1 + cOverallWidth - 1;
				}
			else {
				x1 = (theSize.width - cOverallWidth) / 2;
				x2 = x1 + cOverallWidth - 1;
				y1 = cBorder;
				y2 = theSize.height - cBorder - 1;
				}

			g.setColor(cShadowColor);
			g.drawLine(x1+1, y1+1, x1+1, y2-1);
			g.drawLine(x1+1, y1+1, x2-1, y1+1);

			int freePixel = (mIsHorizontal) ? x2-x1 : y2-y1;
			freePixel -= 2 * cThumbHeight + 2;
			float allSize = mMaxValue - mMinValue;
			mSegmentSize = allSize / (float)freePixel;
			if (mIsHorizontal) {
				mPosition1 = (int)((mLowValue - mMinValue + mSegmentSize/2) / mSegmentSize) + 1;
				mPosition2 = (int)((mHighValue - mMinValue + mSegmentSize/2) / mSegmentSize) + 1 + cThumbHeight + 1;
				}
			else {   // tribute to inverted Y-scale in java
				mPosition1 = (int)((mMaxValue - mHighValue + mSegmentSize/2) / mSegmentSize) + 1;
				mPosition2 = (int)((mMaxValue - mLowValue + mSegmentSize/2) / mSegmentSize) + 1 + cThumbHeight + 1;
				}

			drawThumb(g, x1, y1, mPosition1);
			drawThumb(g, x1, y1, mPosition2);

			if (mPosition2 > mPosition1+cThumbHeight+2) {
				int waterStart = mPosition1 + cThumbHeight + 1;
				int waterStop = mPosition2 - 2;
				for (int i=0; i<14; i++) {
					g.setColor(mUseRedColor ? cWaterRedColor[i] : cWaterBlueColor[i]);
					if (mIsHorizontal)
						g.drawLine(x1+waterStart, y1+i+1, x1+waterStop, y1+i+1);
					else
						g.drawLine(x1+i+1, y1+waterStart, x1+i+1, y1+waterStop);
					}
				}

			g.setColor(cDarkShadowColor);
			g.drawRect(x1, y1, x2-x1, y2-y1);
			}
		}

	public void update(Graphics g) {
		paint(g);
		}

	public float getLowValue() {
		return mLowValue;
		}

	public float getHighValue() {
		return mHighValue;
		}

	public float getMaximumValue() {
		return mMaxValue;
		}

	public float getMinimumValue() {
		return mMinValue;
		}

	/**
	 * Sets high and low values to max and min, respectively.
	 * Sends PruningBarEvents in case of a change.
	 */
	public void reset() {
		boolean highChanged = setHigh(mMaxValue);
		boolean lowChanged = setLow(mMinValue);

		if (highChanged || lowChanged) {
			informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	/**
	 * Updates the low and high values simultaniously, provided the low <= high,
	 * low >= current min, and high <= current max.
	 * @param low
	 * @param high
	 * @param silent if true, PruningBarEvents are suppressed
	 */
	public void setLowAndHigh(float low, float high, boolean silent) {
		boolean lowChanged = setLow(low);
		boolean highChanged = setHigh(high);

		if (highChanged || lowChanged) {
			if (!silent)
				informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	/**
	 * Updates the low value provided the new value is >= current min and <= current high.
	 * Sends PruningBarEvents in case of a successful change.
	 * @param low
	 */
	public void setLowValue(float low) {
		if (setLow(low)) {
			informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	public void setID(int id) {
		mID = id;
		}

	/**
	 * Updates the high value provided the new value is >= current low and <= current max.
	 * Sends PruningBarEvents in case of a successful change.
	 * @param high
	 */
	public void setHighValue(float high) {
		if (setHigh(high)) {
			informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	/**
	 * Updates the maximum value; may update low and high to stay within limits
	 * Sends PruningBarEvents in case of a successful change.
	 * @param max
	 */
	public void setMaximumValue(float max) {
		if (max < mMinValue)
			max = mMinValue;

		if (mMaxValue != max) {
			mMaxValue = max;
			if (mHighValue > mMaxValue)
				mHighValue = mMaxValue;
			if (mLowValue > mHighValue)
				mLowValue = mHighValue;

			informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	/**
	 * Updates the minimum value; may update low and high to stay within limits
	 * Sends PruningBarEvents in case of a successful change.
	 * @param min
	 */
	public void setMinimumValue(float min) {
			// changes the allowed min value; may update low and high to stay within limits
		if (min > mMaxValue)
			min = mMaxValue;

		if (mMinValue != min) {
			mMinValue = min;
			if (mLowValue < mMinValue)
				mLowValue = mMinValue;
			if (mHighValue < mLowValue)
				mHighValue = mLowValue;

			informListeners(false);
			mUpdateNeeded = true;
			repaint();
			}
		}

	/**
	 * Initializes the bar by setting min and low/max and high to the values given.
	 * Does not(!) send PruningBarEvents.
	 * @param min
	 * @param max
	 */
	public void setMinAndMax(float min, float max) {
		mLowValue = mMinValue = min;
		mHighValue = mMaxValue = max;
		mUpdateNeeded = true;
		repaint();
		}

	public void setUseRedColor(boolean useRed) {
		if (mUseRedColor != useRed) {
			mUseRedColor = useRed;
			mUpdateNeeded = true;
			repaint();
			}
		}
	
	public Dimension getMinimumSize() {
		if (mIsHorizontal)
			return new Dimension(4*cThumbHeight, cOverallWidth+2*cBorder);
		else
			return new Dimension(cOverallWidth+2*cBorder, 4*cThumbHeight);
		}

	public Dimension getPreferredSize() {
		if (mIsHorizontal)
			return new Dimension(100, cOverallWidth+2*cBorder);
		else
			return new Dimension(cOverallWidth+2*cBorder, 100);
		}

	public Dimension getMaximumSize() {
		if (mIsHorizontal)
			return new Dimension(Short.MAX_VALUE, cOverallWidth+2*cBorder);
		else
			return new Dimension(cOverallWidth+2*cBorder, Short.MAX_VALUE);
		}

	public void mousePressed(MouseEvent e) {
		if (mIsHorizontal)
			mMousePosition = e.getX();
		else
			mMousePosition = e.getY();

		mClickedArea = 0;
		if (mMousePosition < mPosition1)
			mClickedArea = 0;
		else if (mMousePosition <= mPosition1 + cThumbHeight)
			mClickedArea = 1;
		else if (mMousePosition <= mPosition2)
			mClickedArea = 2;
		else if (mMousePosition <= mPosition2 + cThumbHeight)
			mClickedArea = 3;
		else
			mClickedArea = 0;

		if (!mIsHorizontal  // tribute to inverted Y-scale in java
		 && (mClickedArea == 1 || mClickedArea == 3))
			mClickedArea = 4 - mClickedArea;
		}

	public void mouseReleased(MouseEvent e) {
		informListeners(false);
		}

	public void mouseEntered(MouseEvent e) {}
	public void mouseExited(MouseEvent e) {}
	public void mouseClicked(MouseEvent e) {}

	public synchronized void mouseDragged(MouseEvent e) {
		int position;
		if (mIsHorizontal)
			position = e.getX();
		else
			position = e.getY();

		if (position == mMousePosition)
			return;

		float change = mSegmentSize * (float)(position - mMousePosition);
		if (!mIsHorizontal) // tribute to inverted Y-scale in java
			change = -change;
		if (e.isControlDown())
			change /= 10.0;

		boolean valuesChanged = false;
		switch (mClickedArea) {
		case 1:
			if ((change < 0.0 && mLowValue > mMinValue)
			 || (change > 0.0 && mLowValue < mHighValue))
				valuesChanged = true;

			if (mLowValue + change < mMinValue)
				mLowValue = mMinValue;
			else if (mLowValue + change > mHighValue)
				mLowValue = mHighValue;
			else
				mLowValue += change;
			break;
		case 2:
			if ((change < 0.0 && mLowValue > mMinValue)
			 || (change > 0.0 && mHighValue < mMaxValue))
				valuesChanged = true;

			if (mLowValue + change < mMinValue) {
				mHighValue -= mLowValue - mMinValue;
				mLowValue = mMinValue;
				}
			else if (mHighValue + change > mMaxValue) {
				mLowValue += mMaxValue - mHighValue;
				mHighValue = mMaxValue;
				}
			else {
				mLowValue += change;
				mHighValue += change;
				}
			break;
		case 3:
			if ((change < 0.0 && mHighValue > mLowValue)
			 || (change > 0.0 && mHighValue < mMaxValue))
				valuesChanged = true;

			if (mHighValue + change > mMaxValue)
				mHighValue = mMaxValue;
			else if (mHighValue + change < mLowValue)
				mHighValue = mLowValue;
			else
				mHighValue += change;
			break;
			}

		if (valuesChanged) {
			informListeners(true);
			mMousePosition = position;
			mUpdateNeeded = true;
			repaint();
			}
		}

	public void mouseMoved(MouseEvent e) {}

	public void addPruningBarListener(PruningBarListener listener) {
		mListener.add(listener);
		}

	public void removePruningBarListener(PruningBarListener listener) {
		mListener.remove(listener);
		}

	public void firePruningBarChanged() {
		informListeners(false);
		}

	private void drawThumb(Graphics g, int x1, int y1, int position) {
		int x,y;

		g.setColor(cThumbColor);
		if (mIsHorizontal) {
			g.fillRect(x1+position+1, y1+2, cThumbHeight-1, cOverallWidth-3);
			x = x1+position+2;
			y = y1+3;
			}
		else {
			g.fillRect(x1+2, y1+position+1, cOverallWidth-3, cThumbHeight-1);
			x = x1+3;
			y = y1+position+2;
			}

		g.setColor(cThumbHighlightColor);
		if (mIsHorizontal) {
			g.drawLine(x1+position, y1+1, x1+position+cThumbHeight-2, y1+1);
			g.drawLine(x1+position, y1+1, x1+position, y1+cOverallWidth-2);
			}
		else {
			g.drawLine(x1+1, y1+position, x1+1, y1+position+cThumbHeight-2);
			g.drawLine(x1+1, y1+position, x1+cOverallWidth-2, y1+position);
			}
		for (int i=0; i<5; i++)
			for (int j=0; j<5; j++)
				if (((i + j) & 1) == 0)
					g.drawLine(x+i*2, y+j*2, x+i*2, y+j*2);

		g.setColor(cThumbShadowColor);
		if (mIsHorizontal) {
			g.drawLine(x1+position-1, y1+1, x1+position-1, y1+cOverallWidth-2);
			g.drawLine(x1+position+cThumbHeight, y1+1, x1+position+cThumbHeight, y1+cOverallWidth-2);
			}
		else {
			g.drawLine(x1+1, y1+position-1, x1+cOverallWidth-2, y1+position-1);
			g.drawLine(x1+1, y1+position+cThumbHeight, x1+cOverallWidth-2, y1+position+cThumbHeight);
			}
		for (int i=0; i<5; i++)
			for (int j=0; j<5; j++)
				if (((i + j) & 1) == 0)
					g.drawLine(x+i*2+1, y+j*2+1, x+i*2+1, y+j*2+1);
		}

	private void init() {
		this.setOpaque(false);
		mUpdateNeeded = true;
		addMouseListener(this);
		addMouseMotionListener(this);
		mListener = new ArrayList<PruningBarListener>();
		}

	private boolean setHigh(float value) {
		if (value < mLowValue)
			value = mLowValue;
		else if (value > mMaxValue)
			value = mMaxValue;

		if (value == mHighValue)
			return false;

		mHighValue = value;
		return true;
		}

	private boolean setLow(float value) {
		if (value < mMinValue)
			value = mMinValue;
		else if (value > mHighValue)
			value = mHighValue;

		if (value == mLowValue)
			return false;

		mLowValue = value;
		return true;
		}

	private void informListeners(boolean isAdjusting) {
		for (int i=0; i<mListener.size(); i++)
			mListener.get(i).pruningBarChanged(
				new PruningBarEvent(this, mLowValue, mHighValue, isAdjusting, mID));
		}
	}
